Auto merge of #106025 - matthiaskrgr:rollup-vz5rqah, r=matthiaskrgr

Rollup of 6 pull requests

Successful merges:

 - #105837 (Don't ICE in `check_must_not_suspend_ty` for mismatched tuple arity)
 - #105932 (Correct branch-protection ModFlagBehavior for Aarch64 on LLVM-15)
 - #105960 (Various cleanups)
 - #105985 (Method chain nitpicks)
 - #105996 (Test that async blocks are `UnwindSafe`)
 - #106012 (Clarify that raw retags are not permitted in Mir)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

8 files changed, 99 insertions, 14 deletions

diff --git a/src/test/mir-opt/building/custom/references.immut_ref.built.after.mir b/src/test/mir-opt/building/custom/references.immut_ref.built.after.mir
index 4d38d45c0f4..f5ee1126235 100644
--- a/src/test/mir-opt/building/custom/references.immut_ref.built.after.mir
+++ b/src/test/mir-opt/building/custom/references.immut_ref.built.after.mir
@@ -6,9 +6,8 @@ fn immut_ref(_1: &i32) -> &i32 {
 
     bb0: {
         _2 = &raw const (*_1);           // scope 0 at $DIR/references.rs:+5:13: +5:29
-        Retag([raw] _2);                 // scope 0 at $DIR/references.rs:+6:13: +6:24
-        _0 = &(*_2);                     // scope 0 at $DIR/references.rs:+7:13: +7:23
-        Retag(_0);                       // scope 0 at $DIR/references.rs:+8:13: +8:23
-        return;                          // scope 0 at $DIR/references.rs:+9:13: +9:21
+        _0 = &(*_2);                     // scope 0 at $DIR/references.rs:+6:13: +6:23
+        Retag(_0);                       // scope 0 at $DIR/references.rs:+7:13: +7:23
+        return;                          // scope 0 at $DIR/references.rs:+8:13: +8:21
     }
 }
diff --git a/src/test/mir-opt/building/custom/references.mut_ref.built.after.mir b/src/test/mir-opt/building/custom/references.mut_ref.built.after.mir
index 01bc8a9cd35..8e2ffc33b1a 100644
--- a/src/test/mir-opt/building/custom/references.mut_ref.built.after.mir
+++ b/src/test/mir-opt/building/custom/references.mut_ref.built.after.mir
@@ -6,9 +6,8 @@ fn mut_ref(_1: &mut i32) -> &mut i32 {
 
     bb0: {
         _2 = &raw mut (*_1);             // scope 0 at $DIR/references.rs:+5:13: +5:33
-        Retag([raw] _2);                 // scope 0 at $DIR/references.rs:+6:13: +6:24
-        _0 = &mut (*_2);                 // scope 0 at $DIR/references.rs:+7:13: +7:26
-        Retag(_0);                       // scope 0 at $DIR/references.rs:+8:13: +8:23
-        return;                          // scope 0 at $DIR/references.rs:+9:13: +9:21
+        _0 = &mut (*_2);                 // scope 0 at $DIR/references.rs:+6:13: +6:26
+        Retag(_0);                       // scope 0 at $DIR/references.rs:+7:13: +7:23
+        return;                          // scope 0 at $DIR/references.rs:+8:13: +8:21
     }
 }
diff --git a/src/test/mir-opt/building/custom/references.rs b/src/test/mir-opt/building/custom/references.rs
index c93f6ec624b..a1c896de04c 100644
--- a/src/test/mir-opt/building/custom/references.rs
+++ b/src/test/mir-opt/building/custom/references.rs
@@ -12,7 +12,6 @@ pub fn mut_ref(x: &mut i32) -> &mut i32 {
 
         {
             t = addr_of_mut!(*x);
-            RetagRaw(t);
             RET = &mut *t;
             Retag(RET);
             Return()
@@ -28,7 +27,6 @@ pub fn immut_ref(x: &i32) -> &i32 {
 
         {
             t = addr_of!(*x);
-            RetagRaw(t);
             RET = & *t;
             Retag(RET);
             Return()
diff --git a/src/test/ui/async-await/async-is-unwindsafe.rs b/src/test/ui/async-await/async-is-unwindsafe.rs
new file mode 100644
index 00000000000..56ed2847292
--- /dev/null
+++ b/src/test/ui/async-await/async-is-unwindsafe.rs
@@ -0,0 +1,30 @@
+// edition:2018
+
+fn is_unwindsafe(_: impl std::panic::UnwindSafe) {}
+
+fn main() {
+    // A normal future created by an async block takes a `&mut Context<'_>` argument.
+    // That should not leak through to the whole async block.
+    is_unwindsafe(async {
+        async {}.await; // this needs an inner await point
+    });
+
+    is_unwindsafe(async {
+        //~^ ERROR the type `&mut Context<'_>` may not be safely transferred across an unwind boundary
+        use std::ptr::null;
+        use std::task::{Context, RawWaker, RawWakerVTable, Waker};
+        let waker = unsafe {
+            Waker::from_raw(RawWaker::new(
+                null(),
+                &RawWakerVTable::new(|_| todo!(), |_| todo!(), |_| todo!(), |_| todo!()),
+            ))
+        };
+        let mut cx = Context::from_waker(&waker);
+        let cx_ref = &mut cx;
+
+        async {}.await; // this needs an inner await point
+
+        // in this case, `&mut Context<'_>` is *truly* alive across an await point
+        drop(cx_ref);
+    });
+}
diff --git a/src/test/ui/async-await/async-is-unwindsafe.stderr b/src/test/ui/async-await/async-is-unwindsafe.stderr
new file mode 100644
index 00000000000..d6404b30e74
--- /dev/null
+++ b/src/test/ui/async-await/async-is-unwindsafe.stderr
@@ -0,0 +1,38 @@
+error[E0277]: the type `&mut Context<'_>` may not be safely transferred across an unwind boundary
+  --> $DIR/async-is-unwindsafe.rs:12:19
+   |
+LL |       is_unwindsafe(async {
+   |  ___________________^
+LL | |
+LL | |         use std::ptr::null;
+LL | |         use std::task::{Context, RawWaker, RawWakerVTable, Waker};
+...  |
+LL | |         drop(cx_ref);
+LL | |     });
+   | |     ^
+   | |     |
+   | |_____`&mut Context<'_>` may not be safely transferred across an unwind boundary
+   |       within this `[async block@$DIR/async-is-unwindsafe.rs:12:19: 29:6]`
+   |
+   = help: within `[async block@$DIR/async-is-unwindsafe.rs:12:19: 29:6]`, the trait `UnwindSafe` is not implemented for `&mut Context<'_>`
+   = note: `UnwindSafe` is implemented for `&std::task::Context<'_>`, but not for `&mut std::task::Context<'_>`
+note: future does not implement `UnwindSafe` as this value is used across an await
+  --> $DIR/async-is-unwindsafe.rs:25:17
+   |
+LL |         let cx_ref = &mut cx;
+   |             ------ has type `&mut Context<'_>` which does not implement `UnwindSafe`
+LL |
+LL |         async {}.await; // this needs an inner await point
+   |                 ^^^^^^ await occurs here, with `cx_ref` maybe used later
+...
+LL |     });
+   |     - `cx_ref` is later dropped here
+note: required by a bound in `is_unwindsafe`
+  --> $DIR/async-is-unwindsafe.rs:3:26
+   |
+LL | fn is_unwindsafe(_: impl std::panic::UnwindSafe) {}
+   |                          ^^^^^^^^^^^^^^^^^^^^^^ required by this bound in `is_unwindsafe`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0277`.
diff --git a/src/test/ui/iterators/invalid-iterator-chain.stderr b/src/test/ui/iterators/invalid-iterator-chain.stderr
index d76a4bfb7b3..f3dceca7e41 100644
--- a/src/test/ui/iterators/invalid-iterator-chain.stderr
+++ b/src/test/ui/iterators/invalid-iterator-chain.stderr
@@ -52,14 +52,14 @@ LL |             .sum::<i32>(),
              <i32 as Sum<&'a i32>>
              <i32 as Sum>
 note: the method call chain might not have had the expected associated types
-  --> $DIR/invalid-iterator-chain.rs:20:14
+  --> $DIR/invalid-iterator-chain.rs:25:14
    |
 LL |         vec![0, 1]
    |         ---------- this expression has type `Vec<{integer}>`
 LL |             .iter()
    |              ------ `Iterator::Item` is `&{integer}` here
 LL |             .map(|x| x * 2)
-   |              ^^^^^^^^^^^^^^ `Iterator::Item` changed to `{integer}` here
+   |              -------------- `Iterator::Item` changed to `{integer}` here
 LL |             .map(|x| x as f64)
    |              ----------------- `Iterator::Item` changed to `f64` here
 LL |             .map(|x| x as i64)
@@ -84,14 +84,14 @@ LL |             .sum::<i32>(),
              <i32 as Sum<&'a i32>>
              <i32 as Sum>
 note: the method call chain might not have had the expected associated types
-  --> $DIR/invalid-iterator-chain.rs:32:14
+  --> $DIR/invalid-iterator-chain.rs:33:14
    |
 LL |         vec![0, 1]
    |         ---------- this expression has type `Vec<{integer}>`
 LL |             .iter()
    |              ------ `Iterator::Item` is `&{integer}` here
 LL |             .map(|x| x * 2)
-   |              ^^^^^^^^^^^^^^ `Iterator::Item` changed to `{integer}` here
+   |              -------------- `Iterator::Item` changed to `{integer}` here
 LL |             .map(|x| x as f64)
    |              ^^^^^^^^^^^^^^^^^ `Iterator::Item` changed to `f64` here
 LL |             .filter(|x| *x > 0.0)
diff --git a/src/test/ui/lint/must_not_suspend/tuple-mismatch.rs b/src/test/ui/lint/must_not_suspend/tuple-mismatch.rs
new file mode 100644
index 00000000000..c7e14e42561
--- /dev/null
+++ b/src/test/ui/lint/must_not_suspend/tuple-mismatch.rs
@@ -0,0 +1,9 @@
+#![feature(generators)]
+
+fn main() {
+    let _generator = || {
+        yield ((), ((), ()));
+        yield ((), ());
+        //~^ ERROR mismatched types
+    };
+}
diff --git a/src/test/ui/lint/must_not_suspend/tuple-mismatch.stderr b/src/test/ui/lint/must_not_suspend/tuple-mismatch.stderr
new file mode 100644
index 00000000000..cca8cd9bd89
--- /dev/null
+++ b/src/test/ui/lint/must_not_suspend/tuple-mismatch.stderr
@@ -0,0 +1,12 @@
+error[E0308]: mismatched types
+  --> $DIR/tuple-mismatch.rs:6:20
+   |
+LL |         yield ((), ());
+   |                    ^^ expected tuple, found `()`
+   |
+   = note:  expected tuple `((), ())`
+           found unit type `()`
+
+error: aborting due to previous error
+
+For more information about this error, try `rustc --explain E0308`.